Add a way to review a sent form

[GoogleCodeExporter]

At the time, it is impossible to review a form once it has been sent.
- Before it is sent, a form can be reviewed though "edit a saved form".
- After it is sent, it appears in "Delete sent forms" but the only option is to 
delete it.

This is really problematic, one would like our surveyors to be able to check 
previously collected data when 1/ debriefing with their supervisor, or 2/ 
before submitting a new form concerning the same place.

Thanks in advance.

Original issue reported on code.google.com by gwenael....@gmail.com on 3 Jun 2015 at 9:09